Diloweralkyl acetamidoethyl phosphorodithioates



United States Patent 3,382,300 DILOWERALKYL ACETAMIDOETHYLPHOSPHORODITHIOATES Yoshio Uchiyama and Yoshikatsu Arima, Takaoka-shi,

Kanji Taniguchi, Fujisawa-shi, Nobuo Sato, Koganeiski, and MitsuoAs'ada, Hiratsuka-shi, Japan, assignors to Nippon Soda Kabushiki Kaisha,Chiyoda-ku, Tokyoto, Japan, a company of Japan No Drawing. Filed Dec.31, 1964, Ser. No. 422,522 3 Claims. (Cl. 260-944) ABSTRACT OF THEDISCLOSURE Compounds of the formula R0 s \H PS-CH CHzNH-COCH3 in which Rand R each represents an alkyl radical, which compounds are useful asinsecticides and acaricodes.

This invention relates to novel acetamidoethyl phosphorodithioateshaving high pesticidal activity and to a process for the preparation ofthe same. More specifically, the invention relates to insecticidal andacaricid-al compositions containing one or more of the novel compoundsand further includes methods for combatting insect pests with the samecompositions.

The novel compounds which are provided by this invention are 0.0-dialkylS-(Z-acetamidoethyl) phophorodithioates of the general formula wherein Rand R represent lower alkyl radicals.

A number of argono phosphate insecticides have been used for the controlof many common agricultural pests and certain materials are known :to beeffective as systemic insecticides against insect pests which feed onplants. However, many of these systemic insecticides are relatively orvery highly toxic to human and other warm-blooded animals in handling oruse. Intending to provide practically useful systemic insecticides oflow mammalian toxicity, the numerous derivatives ofsubstituted-amindoethyl phosphorus esters were synthesized and assayedwith respect to several biological activities thereof.

Now, it has been found that the aforesaid novel compounds of the presentinvention are highly effective and selective systemic insecticides andaoaridides with high systemic action against insect pests includingscale insects, aphids, leaf hoppers and spider mites attacking orchardand field crops or other living plants.

Furthermore, it is to be noted that the mammalian toxicity of thesecompounds is markedly reduced in comparison with many otherorganophosphorus systemic insecticides. The lowest mammalian toxiccompound of the series is QO-dimethyl S-(Z-acetamidoethyl)phosphorodithioate, for which the acute oral LD 50 for mice of 300mg./kg. For the 0.0-diethyl S-(Z-acetamidoethyl) phosphorodithioate, thecorresponding figure is 175 mg./ kg. In respect of the former compound,it is sufficiently low in toxicity to permit consideration for itssystemic uses in the veterinary field to control parasites by being fedto animals.

3,382,300 Patented May 7, 1968 The compounds of the present inventionare prepared, by the reaction of following reaction.

RO\fi 5 /PSM+XC;H4NHC|7OH RO I (I) (II) R0 s \II PS-C;II4-NHCCH3 ll RO 0(III) In the formula, R and R are lower alkyl groups such as methyl,ethyl, isopropyl and n-propyl, M is selected from can be prepared by thereaction of Z-acetamidoethanol with methanesulfonyl chloride and4-toluenesulfonyl chloride respectively.

The process of the present invention is carried out generally asfollows:

The Compound (I) and the Compound (H) are mixed in approximate equimolarproportions in a suitable inert solvent and are agitated. As an inertsolvent, hydrocarbons, hydrocarbon halides, alcohols, esters, ketones,nitriles and ethers are preferably employed. The reaction temperatureshould be between 40 C. and 100 C. and the reaction is terminated in 15hours or less.

After the reaction is terminated, the reaction mixture is cooled to roomtemperature and the salts precipitated during the reaction are filteredoff. Then, the solvent is distilled OE, and to the residue water isadded to remove the unreacted portion of the reactants as an aqueoussolution. The oil layer is diluted will benzene, and this solution isthoroughly washed by water and dried, then the solvent is distilled off.Subsequently, the solution is distilled under high vacuum, thecomponents distilled at temperatures of the heating bath of C.-l20 C.are removed and then the desired product is obtained as a yellow viscousoil.

The following non-limiting examples illustrate more precisely thepresent invention.

Example I.(Compound A) C1130 o A mixture of 29 g. of ammonium dimethylphosphoro dithioate in ml. of chloroform was refluxed with agitation,and a solution of 20 g. of l-acetamido-2-chloroethane in 20- ml. ofchloroform was added dropwise. After completion of the addition, themixture was refiuxed with agitation for 6 hrs. Then, the mixture wascooled to room temperature and filtered to remove the precipitate ofammonium chloride formed during the reaction, and the solvent wasdistilled off. The residue was poured into 50 ml. of water, and oillayer was extracted with 50 ml. of benzene. The benzene solution waswashed twice with 20 ml. of water and dried over anhydrous magnesiumsulfate. The dried solution was distilled under a reduced pressure toremove benzene. The residue was retained at 110 C. under 0.1 to 0.2 mm.Hg of vacuum to remove volatile components. Thus, 18.1 g. of lightyellowish orange oil was obtained.

The product was purified through active carbon-benzene columnchromatography.

Refractive index: n =l.5369.

Analysis-Calculated for C H NO PS z C, 29.63%; H, 5.76%; N, 5.76%; P,12.76%; S, 26.35%. Found: C, 29.68%; H, 5.94%; N, 5.94%; P, 12.76%; S,26.20%.

Example II.Compound A Similarly to Example I, 12 g. of ammonium dimethylphosphorodithioate was reacted with 11 g. of l-acetamido- 2-bromethanein 60 ml. of chloroform, and 6 g. of light yellowish oil, refractiveindex 11 =1.5390, was obtained.

Analysis.Calculated: N, 5.76%; P, 12.76%; S, 26. 36%. Found: N, 5.28%;P, 12.76%; S, 26.52%.

Example III.Compound A To a refluxed solution of 15 g. of sodiumdimethyl phosphorodithioatc in 50 ml. of methanol a solution of 10 g. of1-acetamido-Z-chlorethane in 10 ml. of methanol was added dropwise.After completion of the addition, the mixture was refluxed withagitation for 2 hrs., then cooled to room temperature, and filtered toremove precipitate formed during the reaction.

The residue, obtained from the filtrate by removing of methanol, wastreated similarly to Example I, and 5.8 g. of oil, refractive indext n=1.5406, was obtained.

To a refluxed solution of 27 g. of ammonium diethyl phosphorodithioatein 100 ml. of methanol, a solution of 18 g. of l-acetamido-2-chlorethanein 20 ml. of methanol was added dropwise. After completion of theaddition, the mixture was refluxed with agitation for one hour, thencooled to room temperature, precipitated ammonium chloride was filteredoff, and methanol was distilled off. The residue was dissolved in 100ml. of benzene, and the solution was washed with water and dried overanhydrous mangnesium sulfate. Benzene was distilled from the driedsolution under a reduced pressure, and the residue was retained under0.1 to 0.2 mm. Hg of vacuum at a heating bath temperature of 110 C. toremove volatile components. Thus, 17 g. of light yellow oil wasobtained.

Refractive index: n =1.5321.

Analysis.-Calculated for C H NO PS N, 5.18%; P, 11.48%; S, 23.70%.Found: N, 5.19%; P,11.50%; S, 23.45%.

Example V.-Compound A '16 g. of methanesul fonyl chloride was addedportionwise to a solution of 13.2 g. of 2-acetamidoethanol in 250 ml ofchloroform, and the mixture was refluxed with agitation for 11 hrs.Hydrogen chloride gas was evolved during the reaction.

After completion of the reaction, chloroform was distilled off and theresidue was retained under 5 mm. Hg of vacuum on a steam bath to removethe volatile components. 27 g. of oily product, 2-acetamidoethylmethanesulfonatc, was obtained.

The oily product was added to a solution of 26.3 g. of ammonium dimethylphosphorodithioate in 60 ml. of

Cir

chloroform. The mixture was refluxed for 6 hrs., then was 4 treatedsimilarly to the process of Example I. 6 g. of 0.0-dimethyl S-(2acetamidoethyl)phosphorodithioate (11 =1.5427) are obtained.

Analysis.-Calculated for C H NO PS N, 5.76%; P, 12.76%; S, 26.35%.Found: N, 6.16%; P, 13.33%; S, 25.75%.

Example VI.--Compound A 20 g. of 4-toluenesulfonyl chloride was added toa solution of 11.3 g. of 2-acetamidocthanol in 15 ml. of chloroform, andthe mixture was refluxed for 7 hrs., then chloroform was distilled off.

To the viscous oily residue, 30 ml. of benzene was added and the mixturewas refluxed for 5 to 10 minutes, then the upper benzene layer wasdecanted the oil layer remaining. This operation is repeated four times.The oil layer was retained on a steam bath under a reduced pressure toremove benzene completely. Then, 26 g. of oil (1 :15222) was obtained asa residue.

This oil was added to a solution of 17.5 g. of ammonium dimethylphosphorodithioate in 50 ml. of chloroform, and the mixture was refluxedwith agitation for 6 hrs., and treated similarly to the processdescribed in Example I. 5 g. of 0.0-dimethylS-(Z-acetarnidoethyl)phosphorodithioate (n =1.5428) was obtained.

AnaIysis.Calculatcd for C H NO PS N, 5.76%; P, 12.76%; S, 26.35%. Found:N, 5.76%; P, 12.30%; S, 25.98%.

In order that the novel compounds prepared in the above mentionedprocess may be provided for practical purposes, those compounds must beformulated in various types of compositions, for example, dusts,granules, emulsifiable concentrates, wettable powders and aerosols etc.,which can be used conveniently. The following examples illustrate thepreparation and use of the compositions containing the novel compoundsof this invention and the results obtainable through their use but itshould be understood that these examples are intended to be merelyillustrative of the present invention and are not to be construed aslimiting the same.

Example VII The following composition is formulated as an emulsifiableconcentrate by dissolving the active ingredient in a solvent togetherwith a surface-active agent.

Percent 0.0-dimethyl S-(Z-acetamidoethyl) phosphorodithioate (CompoundA) 50 Xylene 43 Polyoxyethylene alkyl aryl ether 7 This composition isdiluted with water to give an aqueous emulsion suitable for use inaccordance .with the 1nvcntion.

Example VIII A wettable powder having the following composition can beprepared by grinding together a mixture of the active ingredient, aninert diluent and a surface active agent and a dispersing agent.

This composition is diluted with water to give an aqueous dispersionsuitable for use in accordance with the inventlon.

Example IX The following dust formulation can be prepared by blending amixture of the active ingredients and inert diluent together and thengrinding to form a homogeneous powder.

Percent Compound A 1 Compound B 0.5 5 Diatomaceous earth 98.5

This composition is applied as a dust suitable for use in accordancewith the invention.

Example X Tests were carried out using the larvae of arrowhead scale(Unaspis yanonensis Kuwana) as test insects. Citrus leaves infested witharrowhead scales were picked from the plants and both cut edges of leafsections were placed on pads of wet absorbent cotton in petri dishes.Compound A and Compound B were sprayed respectively on the leaf sectionseach as an aqueous emulsion at a concentration of 0.05% of the activeingredient, then the treated leaves were held in a rearing roomcontrolled at 20 C. and 70% relative humidity. Mortality counts weremade 13 days after treatment.

scales were tested. Female adults were provided for this experiment, andthe method of Example X was employed. The mortality counts were examined22 days after application.

No. of No. of adults dead Percent before adults mortality treatmentCompound A. 42 41 97. 6 Compound B 48 47 97. 9 Untreated 30 4 l3. 3

Example XII' Adults of arrowhead scales were used in the test. Pottedmandarin orange seedlings, infested with the scale, were test plants.Samples were sprayed respectively on the seedlings as an aqueousdispersion at a concentration of r0 0.05%, then they were kept in agreenhouse during the test period.

Percent of Percent of leaves leaves infested infested with No. of withadults emerged larvae leaves (before (after spraying) spraying) 13 days30 days Compound A 46 84. 4 3. 8 4. 5 Compound B 32 80. 4 4. 4 4. 4Untreated. 18 88. 8 100 100 Example XIII Percent mortality (days aftertreatment) 1 day 2 days Compound A 93 100 Compound B" 89 100 Untreated 00 6 Example XIV Percent mortality (Hours after treatment) 3 hrs. 24 hrs.

Compound A Compound B 68 93 Untreated Control 0 0 Example XV Acaricidalactivity with respect to the two spotted spider mite (Tetranychusteralius L.) was tested. Young kidney bean plants each potted in a 6-cm.pot were used in this experiment. Each twenty adult female mites werereplaced on the plant, and they were kept in a greenhouse for 24 hours.Then samples were sprayed on these plants each as an aqueous dispersion.

Concentration Test Percent of aquatic No. mortality dispersion in 1 day(percent) I 100 Compound A 0.0125

II 100 I 100 Compound B 0. 003

II 100 I 100 Compound B 0.0125

II 100 I 100 0.003

II 100 Untreated 0 Example XVI Tests on citrus red mite (Panonichuscitri L.) were carried out. Seedlings of mandarine orange werehydroponically cultivated in an aquatic dispersion of the sample for oneday, then they were transplanted in a soil pot. Each 30 citrus red miteswere replaced on these plants.

Concentration Percent Percent of the mortality mortality aquatic in 1day in 4 days dispersion (p-p- Compound A 100 100 25 100 5 76. 7 86. 7Compound B 100 100 25 100 5 66. 6 83.3 Untreated 0 0 What we claimis: 1. A compound having the formula R0 S ll P-SCHa-CHzNH(f-CH; R 0

wherein R and R each represents a lower alkyl radical.

2. 0,0-dimetl1yl S- [2-(acetamido)ethyl] phosphorodithioate.

3. 0.0-diethy1 S- [2-(acetamido)ethyl] phosphorodithioate.

References Cited UNITED STATES PATENTS 8/1951 Hook et al. 260944 9/1965Fancher et al. 260944 CHARLES B. PARKER, Primary Examiner.

B. BILLIAN, Assistant Examiner.

